Datasheet LTC3423, LTC3424 (Analog Devices)
| Fabricante | Analog Devices |
| Descripción | Low Output Voltage, 3MHz Micropower Synchronous Boost Converters |
| Páginas / Página | 12 / 1 — FEATURES. DESCRIPTIO. 1.5V to 5.5V Adjustable Output Voltage. Synchronous … |
| Formato / tamaño de archivo | PDF / 211 Kb |
| Idioma del documento | Inglés |
FEATURES. DESCRIPTIO. 1.5V to 5.5V Adjustable Output Voltage. Synchronous Rectification: Up to 95% Efficiency
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LTC3423/LTC3424 Low Output Voltage, 3MHz Micropower Synchronous Boost Converters
U FEATURES DESCRIPTIO
■
1.5V to 5.5V Adjustable Output Voltage
The LTC®3423 and LTC3424 are high efficiency, fixed ■
Synchronous Rectification: Up to 95% Efficiency
frequency, step-up DC/DC converters that can regulate ■
1A Switch Current (LTC3423) or
output voltages as low as 1.5V from a single cell. An
2A Switch Current (LTC3424)
applied voltage of at least 2.7V to the VDD pin is required ■
Fixed Frequency Operation Up to 3MHz
to power the internal control circuitry. ■
Wide Input Range: 0.5V to 5.5V (Operating)
The devices include a 0.16Ω N-channel MOSFET switch ■
Very Low Quiescent Current: 38
µ
A (Burst Mode®
and a 0.21Ω P-channel synchronous rectifier. The LTC3423
Operation)
is intended for applications requiring less than 0.75W of ■ No External Schottky Diode Required output power and the LTC3424 for 1.5W or less. Switching ■ Synchronizable Switching Frequency frequencies up to 3MHz are programmed with an external ■ Burst Mode Enable Control timing resistor and the oscillator can be synchronized to ■ OPTI-LOOP® Compensation an external clock. ■ Very Low Shutdown Current: < 1µA ■ Small 10-Pin MSOP Package Quiescent current is only 38µA in Burst Mode operation,
U
maximizing battery life in portable applications. Burst
APPLICATIO S
Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin ■ Pagers has either a clock or is driven low then the operation is at ■ Handheld Instruments constant fixed frequency. ■ Cordless Phones ■ Wireless Handsets Other features include a 1µA shutdown, thermal shutdown ■ GPS Receivers and current limit. The LTC3423 and LTC3424 are available ■ Battery Backup in the 10-lead MSOP package. For applications requiring , LTC and LT are registered trademarks of Linear Technology Corporation. an output voltage greater than 2.6V, the LTC3401 and Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. LTC3402 are recommended without the need of a separate voltage for the VDD pin.
U TYPICAL APPLICATIO 1-Cell to 1.8V at 600mA Step-Up Converter
VDD = 2.7V TO 5.5V L1
Efficiency
VDD 2.2µH V V IN = 0.9V TO 1.5V OUT 1.8V 100 600mA VIN = 1.5V LTC3424 90 6 4 Burst Mode V R1 DD SW 80 OPERATION 110k VIN = 1.2V 10 7 70 SHDN V V OUT + IN = 0.9V 1 60 3 8 C3 – CELL VIN FB 44µF 50 (2× 22µF) 2 9 MODE/SYNC VC 40 C4 C1 C2 EFFICIENCY (%) 1 5 470pF 30 2.2µF 10µF R2 Rt GND 249k C5 20 V R RC 4.7pF DD = 3.3V t V 30.1k 82k 10 OUT = 1.8V WITH MBRM120T3 SCHOTTKY 00.1 1 10 100 1000 C1: TAIYO YUDEN JMK212BJ225MG OUTPUT CURRENT (mA) 0 = FIXED FREQ C2: TAIYO YUDEN JMK212BJ106MM 1 = Burst Mode OPERATION C3: TAIYO YUDEN JMK325BJ226MM 3223/24 TA02 L1: SUMIDA CD43-2R2M 3423/24 TA01 34234f 1
U FEATURES DESCRIPTIO
■
1.5V to 5.5V Adjustable Output Voltage
The LTC®3423 and LTC3424 are high efficiency, fixed ■
Synchronous Rectification: Up to 95% Efficiency
frequency, step-up DC/DC converters that can regulate ■
1A Switch Current (LTC3423) or
output voltages as low as 1.5V from a single cell. An
2A Switch Current (LTC3424)
applied voltage of at least 2.7V to the VDD pin is required ■
Fixed Frequency Operation Up to 3MHz
to power the internal control circuitry. ■
Wide Input Range: 0.5V to 5.5V (Operating)
The devices include a 0.16Ω N-channel MOSFET switch ■
Very Low Quiescent Current: 38
µ
A (Burst Mode®
and a 0.21Ω P-channel synchronous rectifier. The LTC3423
Operation)
is intended for applications requiring less than 0.75W of ■ No External Schottky Diode Required output power and the LTC3424 for 1.5W or less. Switching ■ Synchronizable Switching Frequency frequencies up to 3MHz are programmed with an external ■ Burst Mode Enable Control timing resistor and the oscillator can be synchronized to ■ OPTI-LOOP® Compensation an external clock. ■ Very Low Shutdown Current: < 1µA ■ Small 10-Pin MSOP Package Quiescent current is only 38µA in Burst Mode operation,
U
maximizing battery life in portable applications. Burst
APPLICATIO S
Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin ■ Pagers has either a clock or is driven low then the operation is at ■ Handheld Instruments constant fixed frequency. ■ Cordless Phones ■ Wireless Handsets Other features include a 1µA shutdown, thermal shutdown ■ GPS Receivers and current limit. The LTC3423 and LTC3424 are available ■ Battery Backup in the 10-lead MSOP package. For applications requiring , LTC and LT are registered trademarks of Linear Technology Corporation. an output voltage greater than 2.6V, the LTC3401 and Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. LTC3402 are recommended without the need of a separate voltage for the VDD pin.
U TYPICAL APPLICATIO 1-Cell to 1.8V at 600mA Step-Up Converter
VDD = 2.7V TO 5.5V L1
Efficiency
VDD 2.2µH V V IN = 0.9V TO 1.5V OUT 1.8V 100 600mA VIN = 1.5V LTC3424 90 6 4 Burst Mode V R1 DD SW 80 OPERATION 110k VIN = 1.2V 10 7 70 SHDN V V OUT + IN = 0.9V 1 60 3 8 C3 – CELL VIN FB 44µF 50 (2× 22µF) 2 9 MODE/SYNC VC 40 C4 C1 C2 EFFICIENCY (%) 1 5 470pF 30 2.2µF 10µF R2 Rt GND 249k C5 20 V R RC 4.7pF DD = 3.3V t V 30.1k 82k 10 OUT = 1.8V WITH MBRM120T3 SCHOTTKY 00.1 1 10 100 1000 C1: TAIYO YUDEN JMK212BJ225MG OUTPUT CURRENT (mA) 0 = FIXED FREQ C2: TAIYO YUDEN JMK212BJ106MM 1 = Burst Mode OPERATION C3: TAIYO YUDEN JMK325BJ226MM 3223/24 TA02 L1: SUMIDA CD43-2R2M 3423/24 TA01 34234f 1